The capsule of Group B streptococci is unusually difficult to dissociate from the organisms. Evidence has been obtained indicating that it is covalently linked to the underlying cell wall. The capsular antigens which are the type antigens of this group are currently being tested on a small scale as vaccines to be given to women in order to prevent neonatal sepsis and meningitis, an increasingly common and devastating disease of newborn children. At present, no suitable method exists for gently isolating the type antigens in toto. Very little information is available on their immunochemistry, and no structural data is available. The proposed project will develop means to lyse enzymatically the Group B cell walls using the muralytic enzymes of Streptomyces albus. Methods for the purification of the antigen will be developed. Attempts will be made to obtain mutants secreting the type specific polysaccharides because they are unable to attach the antigen to their wall covalently. The composition and the structure of the type antigens will be determined by various means including germethylation studies and nuclear magnetic resonance studies. This information will be correlated with the immunochemical characteristics as determined by haptene inhibition.